/*
 Copyright (c) 2006 Eric J. Feminella  <eric@ericfeminella.com>
 All rights reserved.

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is furnished
 to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 @internal
 */

package com.ericfeminella.rpc
{
    import flash.net.NetConnection;
    import flash.net.ObjectEncoding;
    import flash.net.Responder;
    import mx.rpc.IResponder;

    /**
     *
     * Provides a generic base class API for creating AMFPHP 
     * gateway connections and performing remote procedure 
     * calls (RPC) on remote PHP objects.
     * 
     * <p>
     * Classes which extend <code>AMFPHPRemoteGateway</code>
     * implement <code>mx.rpc.IResponder</code> in order to 
     * handle both result and fault events from RPC responses
     * </p> 
     *
     * @example Below is a basic usage example:
     * 
     * <listing version="3.0">
     * package
     * {
     *    import com.ericfeminella.rpc.AMFPHPRemoteGateway;
     *    import mx.rpc.IResponder;
     *
     *    public class TestGateway extends AMFPHPRemoteGateway implements IResponder
     *    {
     *       public function TestGateway(gateway:String)
     *       {
     *          super(gateway, this);
     *       }
     *        
     *       public function result(data:Object) : void
     *       {
     *          // handle result
     *       }
     *        
     *       public function fault(info:Object) : void
     *       { 
     *          // handle fault
     *       }
     *    }
     * }
     *
     * </listing>
     *
     */
    public class AMFPHPRemoteGateway extends NetConnection
    {
        /**
         *
         * Defines the gateway URI in which remote objects 
         * are to be resolved
         *
         */
        protected var gateway:String;

        /**
         *
         * Defines the remote class object in which RPC invocations 
         * are to be executed
         *
         */
        protected var remoteClass:String;

        /**
         *
         * Defines the <code>IResponder</code> instance from which 
         * remote procedure call (RPC) results or faults are forwarded
         *
         * @see mx.rpc.IResponder
         *
         */
        protected var responder:IResponder;
        
        /**
         *
         * Instantiates a new instance of <code>AMFPHPRemoteGateway</code>
         * and sets objectEncoding to ActionScript Message Format 3 (AMF3).
         *
         * @example
         * <listing verison="3.0">
         * 
         * var gateway:String = "http://localhost/amfphp/gateway.php";
         * 
         * </listing>
         * 
         * @param AMFPHP gateway.php URI
         *
         */
        public function AMFPHPRemoteGateway(gatewayURI:String, responder:IResponder)
        {
            this.objectEncoding = ObjectEncoding.AMF3;
            this.gateway = gatewayURI;
            this.responder = responder;
            
            connect( gatewayURI );
        }

        /**
         *
         * Retrieves the class in which remote method invocations
         * are invoked
         *
         * @return remote class which has been registered
         *
         */
        public function get remoteServiceClass() : String
        {
            return remoteClass;
        }

        /**
         *
         * Sets the class in which remote method invocation is to be
         * made. You must include the fully qualified classpath.
         *
         * <p>
         * For example, if a remote class EmailDelegate.php resides
         * in a package data.business, you must set remoteServiceClass
         * to the exact same path:
         * </p>
         *
         * <p>
         * The remoteServiceClass can be set at runtime, therefore a
         * single instance of AMFPHPRemoteGateway may call methods on
         * various objects
         * </p>
         *
         * @param The remote class which is to be invoked
         *
         */
        public function set remoteServiceClass(remoteClass:String) : void
        {
            this.remoteClass = remoteClass;
        }

        /**
         *
         * Retrieves the current gateway URI for this instance of
         * <code>AMFPHPRemoteGateway</code>
         *
         * @return the gateway URI
         *
         */
        public function get gatewayURI() : String
        {
            return gateway;
        }

        /**
         *
         * Performs an rpc method invocation on a remote PHP object
         *
         * @param the method to invoke on the remote object
         * @param a parameter of arbitrary length
         *
         */
        public function invoke(method:String, ...args) : void
        {
            if ( connected )
            {
                var responder:Responder = new Responder( responder.result, responder.fault );
                var method:String = remoteClass + "." + method;

                super.call.apply( null, [method, responder].concat(args) );
            }
            else
            {
                throw new Error("Object is disconnected: Remote Procedure Calls can not be issued");
            }
        }
    }
}